This invention relates to the art of packaging, in particular to a device for dispensing highly stretchable plastic film as a packaging medium.
The growth of the stretch film wrap industry has created demand for devices capable of paying out film under tension as it is wrapped around a package or the like. There are already several such devices in existence, including those shown in U.S. Patents issued to John C. Parry, U.S. Pat. Nos. 4,179,081 and 4,248,392. Those patents disclose devices comprising a flexible grip that, when squeezed, applies a braking force to the core of a film roll, whereby the user can control film tension by squeezing the grips more or less, to brake the film roll. These devices are particularly useful for applying stretch film of substantial width, e.g., twenty inches, and are generally used in pairs, one on either end of the roll.
Other dispensers, some for one-hand operation, have been marketed for dispensing film of narrow widths, on the order of one to four inches. At least one such dispenser includes a spring-biased brake between the handle thereof and the dispensing reel. The bias may be adjusted to provide a preset film tension; however, this tension cannot be varied in use. It is also possible to use grips, as shown in the earlier Parry patents, singly for narrow rolls, but the twisting torque occurring in one-hand operation makes it difficult (or impossible, depending on film width) to control the braking force. A good, inexpensive film dispenser for one-hand stretch wrapping is needed.
It is therefore an object of this invention to provide the industry with a one-hand dispenser for paying out stretch film under controlled tension. A related object is to allow one to vary film tension readily while wrapping an item.
Another object is to eliminate the need to adjust brake settings from item to item or between different gauges or widths of wrapping material.